U.S. patent application number 14/778180 was filed with the patent office on 2016-09-29 for polyolefin-based resin composition.
This patent application is currently assigned to Sumitomo Seika Chemicals Co.,Ltd.. The applicant listed for this patent is SUMITOMO SEIKA CHEMICALS CO., LTD. Invention is credited to Nobutaka FUJIMOTO, Tomoki KAWAKITA, Makiko NAKAHARA, Kiyoshi NISHIOKA, Koh-hei NITTA.
Application Number | 20160280898 14/778180 |
Document ID | / |
Family ID | 51791931 |
Filed Date | 2016-09-29 |
United States Patent
Application |
20160280898 |
Kind Code |
A1 |
FUJIMOTO; Nobutaka ; et
al. |
September 29, 2016 |
POLYOLEFIN-BASED RESIN COMPOSITION
Abstract
This invention provides a polyolefin-based resin composition
excellent in mechanical strength and elasticity. The
polyolefin-based resin composition comprises a polyolefin-based
resin, and, per 100 parts by mass of the polyolefin-based resin,
0.05 to 10 parts by mass of an aliphatic polycarbonate resin and
0.01 to 2 parts by mass of an acid modified polypropylene.
Inventors: |
FUJIMOTO; Nobutaka;
(Himeji-shi, JP) ; NISHIOKA; Kiyoshi; (Himeji-shi,
JP) ; KAWAKITA; Tomoki; (Himeji-shi, JP) ;
NITTA; Koh-hei; (Kanazawa-shi, JP) ; NAKAHARA;
Makiko; (Kanazawa-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SUMITOMO SEIKA CHEMICALS CO., LTD |
Kako-gun |
|
JP |
|
|
Assignee: |
Sumitomo Seika Chemicals
Co.,Ltd.
Kako-gun
JP
|
Family ID: |
51791931 |
Appl. No.: |
14/778180 |
Filed: |
April 24, 2014 |
PCT Filed: |
April 24, 2014 |
PCT NO: |
PCT/JP2014/061512 |
371 Date: |
September 18, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 23/12 20130101;
C08G 64/0208 20130101; C08L 23/10 20130101; C08L 23/10 20130101;
C08L 69/00 20130101; C08L 23/26 20130101; C08L 23/10 20130101; C08L
23/26 20130101; C08L 69/00 20130101 |
International
Class: |
C08L 23/12 20060101
C08L023/12; C08G 64/02 20060101 C08G064/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2013 |
JP |
2013-092242 |
Claims
1. A polyolefin-based resin composition comprising: a
polyolefin-based resin, an aliphatic polycarbonate resin, and an
acid modified polypropylene, wherein, per 100 parts by mass of the
polyolefin-based resin, 0.05 to 10 parts by mass of the aliphatic
polycarbonate resin and 0.01 to 2 parts by mass of the acid
modified polypropylene are present.
2. The polyolefin-based resin composition according to claim 1,
wherein the polyolefin-based resin is polypropylene.
3. The polyolefin-based resin composition according to claim 1,
wherein the aliphatic polycarbonate resin is a polymer obtained by
polymerizing carbon dioxide and an alkylene oxide in the presence
of a metal catalyst.
4. The polyolefin-based resin composition according to claim 1,
wherein the aliphatic polycarbonate resin is polypropylene
carbonate.
5. The polyolefin-based resin composition according to claim 1,
wherein the acid modified polypropylene is maleic acid modified
polypropylene or maleic anhydride modified polypropylene.
6. A molded article obtained from the polyolefin-based resin
composition according to claim 1.
7. An elasticity improving agent for a polyolefin-based resin, the
elasticity improving agent comprising an aliphatic polycarbonate
resin and an acid modified polypropylene.
8. The elasticity improving agent for a polyolefin-based resin
according to claim 7, wherein the acid modified polypropylene is
present in an amount of 0.01 to 2 parts by mass per 0.05 to 10
parts by mass of the aliphatic polycarbonate resin.
9. An aid for improving the elasticity of a polyolefin-based resin,
the aid comprising an aliphatic polycarbonate resin, the aid being
for use in combination with an acid modified polypropylene.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polyolefin-based resin
composition, and more specifically relates to a polyolefin-based
resin composition that is excellent in mechanical strength and
elasticity and a molded article obtained from the composition.
BACKGROUND ART
[0002] Polyolefin-based resins, typically polyethylene and
polypropylene, have been widely used as general-purpose polymers
because they are inexpensive, easy to process, strong, and light,
while being produced at low cost. In particular, polypropylene,
because of its excellent heat resistance and transparency, and
favorable moldability, has been used for a wide range of
applications in, for example, automotive parts, electrical and
electronic components, industrial materials, furniture, stationery,
miscellaneous daily goods, containers, packaging products, toys,
leisure goods, and medical products.
[0003] The performance of polypropylene is closely associated with
its crystalline form, crystallinity, crystalline morphology (size
of spherulites), and the like. Thus, attempts have been made to
control the molecular structure of polypropylene to thereby control
the structures of the crystalline regions and the amorphous regions
on the order of nanometers for the purpose of improving heat
resistance, and mechanical properties, such as scratch-resistance
and rubber elasticity.
[0004] Examples of known methods for improving mechanical
properties, such as yield stress, necking stress, breaking stress,
and breaking strain, without altering the molecular structure of a
polymer include a method comprising modifying the processing
technique, and a method comprising adding an elastomer, an
inorganic filler, or the like to polypropylene to form a composite
material. In particular, a high-performance approach using an
additive can control a wide range of mechanical properties, and the
approach is more economical than the technique for controlling the
molecular structure of polypropylene.
[0005] Patent Document 1 discloses a composition consisting of
polypropylene and a specific propylene-butene-ethylene copolymer,
and the use of the composition for industrial shrink films and
business-use wrap films.
CITATION LIST
Patent Document
[0006] Patent Document 1: JP2002-348417A
SUMMARY OF INVENTION
Technical Problem
[0007] Although, as mentioned above, various modifications with
respect to the mechanical strength of polypropylene-based resin
compositions have been proposed, it has been difficult to improve
elasticity, such as breaking strain, while maintaining mechanical
strength, such as yield stress, necking stress, and breaking
stress. The composition of Patent Document 1 must have a high
content of a propylene-butene-ethylene copolymer to secure
elasticity, which results in a decrease in the amount of
crystalline regions of polypropylene, thus reducing the strength of
the composition.
[0008] An object of the present invention is to provide a
polyolefin-based resin composition excellent in both mechanical
strength and elasticity, and a molded article obtained from the
composition.
Solution to Problem
[0009] The present inventors conducted extensive research to
achieve the above object. The inventors then found that a
polyolefin-based resin composition comprising an aliphatic
polycarbonate resin and an acid modified polypropylene in specific
amounts relative to the amount of the polyolefin-based resin is
excellent in both mechanical strength and elasticity, to thereby
complete the invention. Specifically, the present invention
includes, for example, the subject matter presented in the
following items.
Item 1
[0010] A polyolefin-based resin composition comprising: a
polyolefin-based resin, an aliphatic polycarbonate resin, and an
acid modified polypropylene, wherein, per 100 parts by mass of the
polyolefin-based resin, 0.05 to 10 parts by mass of the aliphatic
polycarbonate resin and 0.01 to 2 parts by mass of the acid
modified polypropylene are present.
Item 2
[0011] The polyolefin-based resin composition according to Item 1,
wherein the polyolefin-based resin is polypropylene.
Item 3
[0012] The polyolefin-based resin composition according to Item 1
or 2, wherein the aliphatic polycarbonate resin is a polymer
obtained by polymerizing carbon dioxide and an alkylene oxide in
the presence of a metal catalyst.
Item 4
[0013] The polyolefin-based resin composition according to any one
of Items 1 to 3, wherein the aliphatic polycarbonate resin is
polypropylene carbonate.
Item 5
[0014] The polyolefin-based resin composition according to any one
of Items 1 to 4, wherein the acid modified polypropylene is maleic
acid modified polypropylene or maleic anhydride modified
polypropylene.
Item 6
[0015] A molded article obtained from the polyolefin-based resin
composition according to any one of Items 1 to 5.
Item 7
[0016] An elasticity improving agent for a polyolefin-based resin,
the elasticity improving agent comprising an aliphatic
polycarbonate resin and an acid modified polypropylene.
Item 8
[0017] The elasticity improving agent for a polyolefin-based resin
according to Item 7, wherein the acid modified polypropylene is
present in an amount of 0.01 to 2 parts by mass per 0.05 to 10
parts by mass of the aliphatic polycarbonate resin.
Item 9
[0018] An aid for improving the elasticity of a polyolefin-based
resin, the aid comprising an aliphatic polycarbonate resin, the aid
being for use in combination with an acid modified
polypropylene.
Advantageous Effects of Invention
[0019] Because the polyolefin-based resin composition according to
the present invention comprises a polyolefin-based resin, and also
comprises a specific amount of an aliphatic polycarbonate resin and
an acid modified polypropylene based on the amount of the
polyolefin-based resin, the polyolefin-based resin composition
exhibits excellent mechanical strength and elasticity.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 shows the measurement results of small-angle X-ray
scattering conducted using test specimens of Example 1 and
Comparative Example 1.
DESCRIPTION OF EMBODIMENTS
[0021] The following describes a polyolefin-based resin composition
according to the present invention in detail.
[0022] The polyolefin-based resin composition according to the
present invention comprises, in addition to a polyolefin-based
resin, specific proportions of an aliphatic polycarbonate resin and
an acid modified polypropylene.
[0023] The polyolefin-based resin usable in the present invention
is a polymer comprising monomer units derived from an olefin.
Examples include polyethylene-based resins, ethylene/carboxylic
acid alkenyl ester copolymer resins, ethylene/unsaturated
carboxylic acid alkyl ester copolymer resins, polypropylene-based
resins, polybutene-based resins, and poly(4-methyl-1-pentene)-based
resins.
[0024] Examples of preferable polyethylene-based resins include
polyethylene. Polyethylene is not particularly limited, and
examples of usable polyethylene include low-density polyethylene,
linear low-density polyethylene, medium-density polyethylene, and
high-density polyethylene.
[0025] Examples of "carboxylic acid alkenyl esters" of
ethylene/carboxylic acid alkenyl ester copolymer resins include
vinyl acetate, vinyl propionate, vinyl butylate, isopropenyl
acetate, and allyl acetate. Of these, vinyl acetate is preferable.
Specifically, as an ethylene/carboxylic acid alkenyl ester
copolymer resin, an ethylene/vinyl acetate copolymer is
particularly preferable.
[0026] Examples of "unsaturated carboxylic acid alkyl esters" of
ethylene/unsaturated carboxylic acid alkyl ester copolymer resins
include methyl acrylate, ethyl acrylate, propyl acrylate, methyl
methacrylate, ethyl methacrylate, and propyl methacrylate. Of
these, methyl acrylate and methyl methacrylate are preferable.
Specifically, as an ethylene/unsaturated carboxylic acid alkyl
ester copolymer resin, an ethylene/methyl acrylate copolymer and an
ethylene/methyl methacrylate copolymer are particularly
preferable.
[0027] Preferable examples of polypropylene-based resins include
polypropylene and copolymers of propylene with one or more other
olefins. Examples of preferable "one or more other olefins" as used
herein include ethylene, butene, pentene, hexene, and octane. The
"one or more other olefins" for use refers to a single olefin or a
combination of two or more olefins (i.e., propylene with a single
olefin, or propylene with a combination of two or more other
olefins can be made into a copolymer). More specifically, as a
polypropylene-based resin, polypropylene, a propylene/ethylene
copolymer, a propylene/ethylene/butene copolymer, a
propylene/butene copolymer, a propylene/hexene copolymer, a
propylene/octene copolymer, and the like are preferable. Propylene
and a propylene/ethylene copolymer are particularly more
preferable.
[0028] Polyolefin-based resins can be used singly or in a
combination of two or more. Of polyolefin-based resins,
polypropylene-based resins are preferably used from the standpoint
of excellent compatibility with aliphatic polycarbonate resins. At
least one resin selected from the group consisting of polypropylene
and copolymers of propylene with one or more other olefins is more
preferably used. Propylene/ethylene copolymers are yet more
preferably used.
[0029] Examples of methods for producing a polyolefin-based resin
include methods comprising radical polymerization of an olefin
using an initiator, such as a peroxide, and methods comprising
polymerization of an olefin using a gas-phase technique, solution
technique, or the like in the presence of a polymerization
catalyst. Examples of usable polymerization catalysts include
Ziegler-Natta catalysts and metallocene catalysts.
[0030] The molecular weight of the above-described polyolefin-based
resins is not particularly limited. For example, the weight average
molecular weight is preferably within the range of 20,000 to
6,000,000, more preferably 30,000 to 6,000,000, and yet more
preferably 100,000 to 5,000,000.
[0031] The polyolefin-based resin having a weight average molecular
weight of 20,000 or more can further improve the mechanical
strength of the resulting polyolefin-based resin composition. The
polyolefin-based resin having a weight average molecular weight of
6,000,000 or less makes it easier to mold the resulting
polyolefin-based resin composition. The weight average molecular
weight is determined by measurement in accordance with the
later-described method. The weight average molecular weight is a
value determined by preparing a 0.5% by mass solution of a
polyolefin-based resin in chloroform, conducting a measurement by
high-performance liquid chromatography, and making a comparison
with polystyrene having a known weight average molecular weight,
which has been measured under the same conditions. The measurement
conditions are as follows. [0032] Column: GPC Column [0033] (Trade
name of Tosoh Corporation: TSK GEL Multipore FH.sub.XL-M) [0034]
Column Temperature: 40.degree. C. [0035] Eluate: Chloroform [0036]
Flow Rate: 1 mL/min
[0037] The fluidity of a resin is indicated by the melt flow rate
(MFR, unit: g/10 minutes), which is measured in accordance with,
for example, the procedure described in JIS K 7210:1999. The
polyolefin-based resin usable in the present invention preferably
has a melt flow rate within the range of 0.5 to 100 (g/10 minutes),
and more preferably 1 to 75 (g/10 minutes), which is measured at a
temperature of 230.degree. C. with a 2.16 kg load in accordance
with the procedure. The polyolefin-based resin having an MFR of 0.5
or more provides a polyolefin-based resin composition having a not
excessively low fluidity, which is therefore easy to mold by
injection molding in a desirable manner.
[0038] The polyolefin-based resin having an MFR of 100 or less can
further improve the weatherability of the resulting
polyolefin-based resin composition.
[0039] The aliphatic polycarbonate resin usable in the present
invention is not particularly limited. Preferable examples include
polymers obtained by a polymerization reaction of an alkylene oxide
and carbon dioxide in the presence of a metal catalyst.
[0040] Examples of alkylene oxides include ethylene oxide,
propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide,
1-pentene oxide, 2-pentene oxide, 1-hexene oxide, 1-octene oxide,
1-decene oxide, cyclopentene oxide, cyclohexene oxide, styrene
oxide, vinylcyclohexene oxide, 3-phenylpropylene oxide,
3,3,3-trifluoropropylene oxide, 3-naphthyl propylene oxide,
3-phenoxy propylene oxide, 3-naphthoxy propylene oxide, butadiene
monoxide, 3-vinyloxy propylene oxide, and 3-trimethylsilyloxy
propylene oxide. Of these alkylene oxides, from the standpoint of
their high polymerization reactivity with carbon dioxide, ethylene
oxide and propylene oxide are preferably used, and propylene oxide
is more preferably used. These alkylene oxides can be used singly
or in a combination of two or more. For example, the aliphatic
polycarbonate resin obtained by using ethylene oxide alone is
polyethylene carbonate, and the aliphatic polycarbonate resin
obtained by using propylene oxide alone is polypropylene
carbonate.
[0041] Examples of metal catalysts include aluminum catalysts and
zinc catalysts. Of these, from the standpoint of their high
polymerization reactivity in a polymerization reaction of an
alkylene oxide and carbon dioxide, zinc catalysts are preferably
used. Of zinc catalysts, organozinc catalysts are more preferably
used.
[0042] Examples of organozinc catalysts include zinc acetate,
diethylzinc, and dibutylzinc; and those obtained by reacting a zinc
compound with a compound such as a primary amine, a divalent
phenol, a divalent aromatic carboxylic acid, an aromatic hydroxylic
acid, an aliphatic dicarboxylic acid, and an aliphatic
monocarboxylic acid. Of these, an organozinc catalyst obtained by
reacting a zinc compound with an aliphatic dicarboxylic acid and an
aliphatic monocarboxylic acid is preferable because of its high
polymerization activity.
[0043] The amount of the metal catalyst for use in the
polymerization reaction is preferably 0.001 to 20 parts by mass,
and more preferably 0.01 to 10 parts by mass, per 100 parts by mass
of the alkylene oxide. The metal catalyst in an amount of 0.001
parts by mass or more preferably facilitates the polymerization
reaction. The metal catalyst in an amount of 20 parts by mass or
less produces favorable effects that match the amount of catalyst
added.
[0044] The method of the polymerization reaction between an
alkylene oxide and carbon dioxide in the presence of a metal
catalyst is not particularly limited. Examples include a method
comprising charging an autoclave with the above-described alkylene
oxide and a metal catalyst, optionally with a reaction solvent,
mixing them, and injecting carbon dioxide thereinto with pressure
to allow a reaction.
[0045] The reaction solvent for optional use in the polymerization
reaction is not particularly limited, and a variety of organic
solvents can be used. Specific examples include aliphatic
hydrocarbon-based solvents, such as pentane, hexane, octane,
decane, and cyclohexane; aromatic hydrocarbon-based solvents, such
as benzene, toluene, and xylene; halogenated hydrocarbon-based
solvents, such as chloromethane, methylenedichloride, chloroform,
carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, ethyl
chloride, trichloroethane, 1-chloropropane, 2-chloropropane,
1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane,
chlorobenzene, and bromobenzene; and carbonate-based solvents, such
as dimethyl carbonate, diethyl carbonate, and propylene
carbonate.
[0046] The amount of the reaction solvent is preferably 300 to
10,000 parts by mass per 100 parts by mass of an alkylene oxide,
from the standpoint of achieving a smooth reaction.
[0047] The pressure of carbon dioxide for use in the polymerization
reaction is not particularly limited, but is typically preferably
0.1 to 20 MPa, more preferably 0.1 to 10 MPa, and yet more
preferably 0.1 to 5 MPa.
[0048] The temperature for the polymerization reaction is not
particularly limited, but preferably 30 to 100.degree. C., and more
preferably 40 to 80.degree. C. A polymerization reaction
temperature of 30.degree. C. or more enables the polymerization
reaction to proceed in a short time. A polymerization reaction
temperature of 100.degree. C. or less can decrease the likelihood
of a side reaction, and further increase the yield. The
polymerization reaction time cannot be generalized because it
depends on the polymerization reaction temperature, but is
typically preferably 2 to 40 hours.
[0049] After completion of the polymerization reaction, the
reaction product is separated by filtration or the like, optionally
washed with a solvent or the like, and dried to obtain an aliphatic
polycarbonate resin. In the present invention, a single aliphatic
polycarbonate resin or a combination of two or more aliphatic
polycarbonate resins can be used.
[0050] The aliphatic polycarbonate resin for use in the present
invention preferably has a weight average molecular weight of
10,000 to 2,000,000, more preferably 20,000 to 1,000,000, and yet
more preferably 20,000 to 750,000. The weight average molecular
weight is a value determined by preparing a 0.5% by mass solution
of an aliphatic polycarbonate resin in chloroform and measuring the
weight average molecular weight in the same manner as in the
aforementioned measurement of the weight average molecular weight
of a polyolefin-based resin.
[0051] An aliphatic polycarbonate resin having a weight average
molecular weight of less than 10,000 may decrease the mechanical
strength of the resulting polyolefin-based resin composition. An
aliphatic polycarbonate resin having a weight average molecular
weight of 2,000,000 or less exhibits increased dispersibility in a
polyolefin-based resin, and thus improves the weatherability of the
resulting polyolefin-based resin composition.
[0052] In the polyolefin-based resin composition according to the
present invention, the minimum amount of the aliphatic
polycarbonate resin is 0.05 parts by mass, preferably 0.5 parts by
mass, and more preferably 1 part by mass, per 100 parts by mass of
a polyolefin-based resin. The maximum amount of the aliphatic
polycarbonate resin is 10 parts by mass, preferably 7.5 parts by
mass, and more preferably 5 parts by mass, per 100 parts by mass of
a polyolefin-based resin. In particular, the aliphatic
polycarbonate resin is present in an amount of 0.05 to 10 parts by
mass, preferably 0.5 to 10 parts by mass, more preferably 0.5 to
7.5, and yet more preferably 1 to 5 parts by mass, per 100 parts by
mass of a polyolefin-based resin.
[0053] The aliphatic polycarbonate resin in an amount of more than
10 parts by mass may decrease the mechanical strength of the
polyolefin-based resin composition. The aliphatic polycarbonate
resin in an amount of less than 0.05 parts by mass may decrease the
elasticity of the polyolefin-based resin composition.
[0054] Preferable examples of acid modified polypropylenes for use
in the present invention include polypropylenes that are
graft-modified with, for example, a dicarboxylic acid, an anhydride
thereof, or a derivative of an unsaturated carboxylic acid.
[0055] Examples of dicarboxylic acids include maleic acid, fumaric
acid, and itaconic acid. Examples of anhydrides of dicarboxylic
acids include maleic anhydride, fumaric anhydride, and itaconic
anhydride. Examples of derivatives of unsaturated carboxylic acids
include maleic acid monoethyl ester, maleic acid diethyl ester,
fumaric acid monomethyl ester, fumaric acid dimethyl ester,
itaconic acid monoethyl ester, itaconic acid diethyl ester, maleic
acid monoamide, maleic acid diamide, fumaric acid monoamide,
fumaric acid diamide, itaconic acid monoamide, and itaconic acid
diamide. Of these, maleic acid modified polypropylene and maleic
anhydride modified polypropylene are preferably used from the
standpoint of their excellent plasticizing effect and ease of mold
processing of the resulting polyolefin-based resin composition.
Acid modified polypropylenes may be used singly or in a combination
of two or more.
[0056] The molecular weight of an acid modified polypropylene is
not particularly limited insofar as the advantageous effects of the
present invention are not impaired. For example, an acid modified
polypropylene preferably has a weight average molecular weight of
2,000 to 100,000, more preferably 5,000 to 100,000, and yet more
preferably 10,000, to 50,000.
[0057] An acid modified polypropylene having a weight average
molecular weight of 10,000 or more enables an aliphatic
polycarbonate resin to disperse more homogeneously in the resulting
polyolefin-based resin composition, thereby further desirably
increasing the weatherability of the polyolefin-based resin
composition. An acid modified polypropylene having a weight average
molecular weight of 1,000,000 or less makes it easier to process
the resulting polyolefin-based resin composition by molding.
[0058] The weight average molecular weight is a value determined by
preparing a 0.5% by mass solution of an acid modified polypropylene
in chloroform and measuring the weight average molecular weight in
the same manner as in the aforementioned measurement of the weight
average molecular weight of a polyolefin-based resin.
[0059] The acid modified polypropylene MFR (measured in accordance
with the method described in JIS K 7210:1999) is within the range
of 1 to 100 (g/10 minutes), and preferably 2 to 50 (g/10 minutes)
at a temperature of 230.degree. C. under a 2.16 kg load. An acid
modified polypropylene having an MFR of 1 or more makes it easier
to process the resulting polyolefin-based resin composition by
molding. A polyolefin-based resin having an MFR of 100 or less
enables an aliphatic polycarbonate resin to disperse more
homogeneously in the resulting polyolefin-based resin composition,
thereby further increasing the weatherability of the
polyolefin-based resin composition.
[0060] In the polyolefin-based resin composition according to the
present invention, the minimum amount of the acid modified
polypropylene is 0.01 parts by mass, and preferably 0.1 parts by
mass, per 100 parts by mass of a polyolefin-based resin. The
maximum amount of the acid modified polypropylene is 2 parts by
mass, and preferably 1.5 parts by mass, per 100 parts by mass of a
polyolefin-based resin. In particular, the acid modified
polypropylene is present in an amount of 0.01 to 2 parts by mass,
preferably 0.1 to 2 parts by mass, and more preferably 0.1 to 1.5
parts by mass, per 100 parts by mass of a polyolefin-based
resin.
[0061] The acid modified polypropylene in an amount of 2 parts by
mass or less produces effects matched to the amount of acid
modified polypropylene added, and this is therefore economical. The
acid modified polypropylene in an amount of 0.01 parts by mass or
more can further increase the elasticity of the polyolefin-based
resin composition.
[0062] The method for producing the polyolefin-based resin
composition according to the present invention is not particularly
limited. Examples include: a method comprising mixing, in no
particular order, a polyolefin-based resin, an aliphatic
polycarbonate resin, and an acid modified polypropylene using a
Henschel mixer, a ribbon blender, a blender, or the like, to form a
homogeneous mixture, and melt-kneading the mixture; and a method
comprising dissolving a polyolefin-based resin, an aliphatic
polycarbonate resin, and an acid modified polypropylene in a
solvent or the like, mixing them, and removing the solvent. Of
these production methods, the method comprising melt-kneading a
polyolefin-based resin, an aliphatic polycarbonate resin, and an
acid modified polypropylene is preferably used from the standpoint
of the simplicity of producing the composition as well as the
capability of producing a homogeneous composition. For example, a
method comprising melt-kneading an aliphatic polycarbonate resin
and an acid modified polypropylene to obtain a mixture, adding a
polyolefin-based resin to the mixture, and melt-kneading the
resulting mixture is preferably used.
[0063] The method for melt-kneading a polyolefin-based resin, an
aliphatic polycarbonate resin, and an acid modified polypropylene
is not particularly limited. Examples include melt-kneading methods
using a biaxial vent extruder, a Banbury mixer, a kneader, a roll
kneader, or the like.
[0064] The shape of the polyolefin-based resin composition
according to the present invention is not restricted, and any
shape, such as a strand, a sheet, a flat plate, and a pellet formed
by cutting a strand in a proper length, is applicable. In
particular, a pellet of 2 to 50 mm in length is preferable in order
to subject it to injection molding, which is an easy mold
processing technique.
[0065] Insofar as the advantageous effects of the present invention
are not impaired, the polyolefin-based resin composition according
to the present invention may comprise other additives, for example,
antioxidants; metal deactivators; thermal stabilizers;
neutralizers; stabilizers such as ultraviolet absorbers; defoamers;
flame retardants; flame retardant aids; dispersants; antistats;
lubricants; anti-blocking agents such as silica; colorants such as
dyes and pigments; rubber; plasticizers; plate-like or powdery
inorganic compounds such as glass flakes, mica, glass powder, glass
beads, talc, clay, alumina, carbon black, and wollastonite;
whiskers; and the like. The amount of an additive is, for example,
preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts
by mass, and yet more preferably 0.5 to 3 parts by mass, per 100
parts by mass of a polyolefin-based resin composition.
[0066] The molded article according to the present invention is
obtained from the polyolefin-based resin composition according to
the present invention.
[0067] Examples of methods for obtaining the molded article include
injection molding, compression molding, injection compression
molding, gas-assisted injection molding, foam injection molding,
inflation, T-die extrusion, calendaring, blow molding, vacuum
molding, and pressure molding. When the molded article of the
present invention is in the form of a film or sheet, such a molded
article may constitute at least one layer of a multi-layered
structure produced by inflation, T-die extrusion, or calendaring
conducted additionally using different resins. Alternatively, the
molded article may be formed as a multi-layered film or sheet by
extrusion lamination, thermal lamination, dry lamination, or the
like. The obtained film or sheet can be mono- or biaxially
stretched for use by roll stretching, tenter stretching, tubular
stretching, or the like. The molded article according to the
present invention may be subjected to a surface treatment, such as
corona discharge treatment, flame treatment, plasma treatment, and
ozone treatment.
[0068] The molded article of the present invention can be used as
electrical and electronic components, building components, auto
parts, machine components, daily commodities, industrial materials,
and the like. Specific examples of electrical and electronic
components include housings and internal parts of photocopy
machines, personal computers, printers, electronic musical
instruments, home-use game consoles, and portable game players.
Specific examples of building components include curtain parts,
blind parts, roof panels, thermal insulation walls, adjusters,
floor posts, and ceiling hoisting attachments. Specific examples of
auto parts include fenders, over fenders, grille guards, cowl
louvers, wheel caps, side protectors, side moldings, side lower
skirts, front grilles, roof rails, rear spoilers, bumpers, lower
instrument panels, and trims. Specific examples of machine
components include gears, screws, springs, bearings, levers, cams,
ratchets, and rollers. Specific examples of daily commodities
include cutlery, toiletry products, carton boxes, packaging films,
wrapping films, laminated paper bags, prepaid cards, blades for
cling films, food trays, garbage bags, laminated bags, pouches,
labels, thermoformed items, packing bands, woven or knitted goods
(garments, interior accessories), carpets, hygienic materials,
packaging films, containers, and cups for food. Specific examples
of industrial materials include textile binders, paper coating,
adhesives, agricultural films, spun yarn, slit yarn, ropes, nets,
filters, woven or knitted goods (industrial materials), compost
bags, waterproof sheets, and sandbags.
[0069] The mechanism for how the present invention can provide a
polyolefin-based resin composition having excellent mechanical
strength and elasticity remains to be elucidated. While not wishing
to be bound by any theory, we believe that the aliphatic
polycarbonate resin disperses into the amorphous regions of the
polyolefin-based resin via the acid modified polypropylene without
affecting the crystalline form, crystallinity, and crystalline
morphology (size of spherulites) of the polyolefin-based resin,
which helps to maintain the mechanical strength and suppress the
interfacial debonding between the polyolefin-based resin and the
aliphatic polycarbonate resin during extension and contraction,
thereby giving a polyolefin-based resin composition having both
mechanical strength and elasticity.
[0070] The scope of the present invention encompasses an elasticity
improving agent for a polyolefin-based resin, comprising an
aliphatic polycarbonate resin and an acid modified polypropylene.
The aliphatic polycarbonate resin and the acid modified
polypropylene usable for the elasticity improving agent are the
same as those usable for the polyolefin-based resin composition
according to the present invention. The polyolefin-based resin to
which the elasticity improving agent is applied is also the same as
those usable for the polyolefin-based resin composition according
to the present invention.
[0071] The elasticity improving agent preferably comprises 0.01 to
2 parts by mass of an acid modified polypropylene per 0.05 to 10
parts by mass of an aliphatic polycarbonate resin.
[0072] More specifically, the elasticity improving agent comprises,
per 5 parts by mass of an aliphatic polycarbonate resin, preferably
0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass,
and yet more preferably 0.2 to 2 parts by mass of an acid modified
polypropylene.
[0073] The elasticity improving agent can be produced by various
methods, such as a method comprising mixing an aliphatic
polycarbonate resin and an acid modified polypropylene using a
Henschel mixer, a ribbon blender, a blender, or the like to produce
a homogeneous mixture, and a method comprising, in addition to the
steps of the former method, melt-kneading the mixture.
[0074] The elasticity improving agent, when added to a
polyolefin-based resin, improves the elasticity of the
polyolefin-based resin while maintaining the mechanical strength.
In other words, the elasticity improving agent can provide a
polyolefin-based resin composition maintaining the mechanical
strength of a polyolefin-based resin while exhibiting improved
elasticity. For example, the elasticity improving agent is
preferably added in an amount of 1 to 20 parts by mass, and more
preferably 2 to 10 parts by mass, per 100 parts by mass of a
polyolefin-based resin. Specific examples of the methods for adding
the elasticity improving agent to a polyolefin-based resin include
melt-kneading. The melt-kneading method is not particularly
limited, but examples include a melt-kneading method using a
biaxial vent extruder, a Banbury mixer, a kneader, a roll kneader,
or the like.
[0075] The scope of the present invention encompasses an aid for
improving the elasticity of a polyolefin-based resin with the aid
comprising an aliphatic polycarbonate resin and being for use in
combination with an acid modified polypropylene.
[0076] The aid for improving elasticity, when used in combination
with an acid modified polypropylene and added to a polyolefin-based
resin, improves the elasticity of the polyolefin-based resin while
maintaining the mechanical strength. The aid can also be used in
the production of the aforementioned elasticity improving agent.
The aliphatic polycarbonate resin used in the aid for improving
elasticity, the acid modified polypropylene used in combination
with the aid, the polyolefin-based resin to which the aid is
applied, the ratio of the acid modified polypropylene to the
aliphatic polycarbonate resin contained in the aid, the method for
combining the acid modified polypropylene with the aliphatic
polycarbonate resin-containing aid, the ratio of the aliphatic
polycarbonate resin contained in the aid to the polyolefin-based
resin, the method for applying the aliphatic polycarbonate
resin-containing aid to the polyolefin-based resin, and the like
are the same as those described for the polyolefin-based resin
composition according to the present invention and the elasticity
improving agent for a polyolefin-based resin according to the
present invention.
[0077] The scope of the present invention also encompasses a method
for improving the elasticity of a polyolefin-based resin by adding
the above-described elasticity improving agent for a
polyolefin-based resin to a polyolefin-based resin, and a method
for producing the above-described elasticity improving agent by
adding the above-described aid for improving the elasticity of a
polyolefin-based resin to be used in combination with an acid
modified polypropylene to an acid modified polypropylene. The
polyolefin-based resin and acid modified polypropylene used in
these methods, the amount of the elasticity improving agent, the
amount of the aid for improving elasticity, the method for adding
the elasticity improving agent, and the method for adding the aid
for improving elasticity are the same as those described for the
polyolefin-based resin composition according to the present
invention and the elasticity improving agent for a polyolefin-based
resin according to the present invention.
EXAMPLES
[0078] The following Production Examples, Examples, and Comparative
Examples describe the present invention in detail. However, the
present invention is not limited to these Examples.
Evaluation
[0079] The measurement of the weight average molecular weight of
the aliphatic polycarbonate resin obtained in the Production
[0080] Example, the differential scanning calorimetry (DSC
Measurement) and the measurement of small-angle X-ray scattering
(SAXS Measurement) of the polyolefin-based resin compositions
obtained in the Examples and Comparative Examples, and a uniaxial
tensile test for the polyolefin-based resin compositions were
conducted in accordance with the following procedure.
(1) Measurement of Weight Average Molecular Weight (Mw)
[0081] A 0.5% by mass solution of a resin to be measured in
chloroform was prepared, and measurement was conducted by
high-performance liquid chromatography. Comparison was made with
polystyrene having a known weight average molecular weight, which
was measured under the same conditions, and the molecular weight
was determined. The number average molecular weight (Mn) was also
determined in the same manner, and the molecular weight
distribution (Mw/Mn) was determined. The measurement conditions are
described below. [0082] Measuring Instrument: HLC-8020
(manufactured by Tosoh Corporation) [0083] Column: GPC Column
[0084] (Trade Name of Tosoh Corporation, TSK GEL Multipore
H.sub.XL-M) [0085] Column Temperature: 40.degree. C. [0086] Eluate:
Chloroform [0087] Flow Rate: 1 mL/min
(2) Differential Scanning Calorimetry (DSC Measurement)
[0088] The crystallization temperature and melting temperature of
the polyolefin-based resin compositions were measured using the
following instruments. [0089] Measuring Instrument: Diamond DSC
manufactured by PerkinElmer Inc. [0090] Temperature Rising Rate:
20.degree. C./min [0091] Temperature Falling Rate: 20.degree.
C./min [0092] Measuring Temperature Range: 0 to 230.degree. C.
(3) Measurement of Small-Angle X-ray Scattering (SAXS
Measurement)
[0093] The crystalline morphology of each polyolefin-based resin
composition was observed using the following instrument. [0094]
Measuring Instrument: NANO-Viewer System manufactured by Rigaku
Corporation [0095] X-ray: CuK .alpha. ray (.lamda.=0.154 nm)
(4) Hot-Press Molding
[0096] Test specimens for use in a tensile test were prepared by
hot-press molding. [0097] Instrument: Desktop Hot Press
manufactured by Techno Supply [0098] Press Temperature: 230.degree.
C. [0099] Pressure: 20 MPa
(5) Tensile Test
[0100] The yield stress, necking stress, breaking stress, and
breaking strain were measured using the following test specimens
and instrument in accordance with JIS K 7161:1994. A test specimen
having a higher yield stress and necking stress is considered to be
a hard material with excellent strength. A test specimen having a
higher breaking stress and breaking strain is considered to be a
resilient material with excellent elasticity. The necking stress
refers to a stress value observed while necking occurs in the
measured test specimen. The "yield stress," "breaking stress," and
"breaking strain" as used herein, respectively, correspond to the
"tensile yield stress," "tensile stress at break," and "tensile
strain at break" in JIS K 7161:1994. [0101] Test specimens:
Dumbbell Shape (Dimension of Neck Part: 10 mm in length, 4 mm in
width, and 0.2 mm in thickness) (dumbbell shape) [0102] Measuring
Instrument: MODEL 4466, Tensile Testing Machine manufactured by
Instron [0103] Tension Rates: 40, 80, 120 mm/min [0104] Measurement
Temperature: 25.degree. C.
Production Example 1
Production of Organozinc Catalyst
[0105] A 300-mL four-necked flask equipped with a stirrer, a
nitrogen gas feeding tube, a thermometer, and a reflux condenser
was charged with 8.1 g (100 mmol) of zinc oxide, 12.7 g (96 mmol)
of glutaric acid, 0.1 g (2 mmol) of acetic acid, and 130 g (150 mL)
of toluene. Subsequently, the atmosphere of the reaction system was
replaced by a nitrogen atmosphere, and the temperature was raised
to 55.degree. C., followed by stirring at the same temperature for
four hours to allow a reaction. The temperature was then raised to
110.degree. C., and the mixture was stirred at the same temperature
for four hours to allow azeotropic dehydration to remove only
water. The reaction mixture was then cooled to room temperature,
thereby giving a reaction liquid containing an organozinc
catalyst.
[0106] A portion of the reaction liquid was separated and filtered
to obtain an organozinc catalyst. The organozinc catalyst was
analyzed by IR spectroscopy using an instrument manufactured by
Thermo Nicolet Japan Inc. (trade name: Avatar 360). The results
showed no peak of carboxy group.
Production Example 2
Production of Polypropylene Carbonate
[0107] The atmosphere of a 1-L autoclave equipped with a stirrer, a
gas feeding tube, and a thermometer was replaced by a nitrogen
atmosphere in advance, and the autoclave was charged with 8.0 mL of
the reaction liquid containing an organozinc catalyst obtained in
Production Example 1 (1.0 g of an organozinc catalyst was
contained), 131 g (200 mL) of hexane, and 46.5 g (0.80 mole) of
propylene oxide. Subsequently, carbon dioxide was added thereto
while stirring to replace the atmosphere of the reaction system by
a carbon dioxide atmosphere. Carbon dioxide was added until the
pressure of the reaction system reached 1.5 MPa. The temperature
was then raised to 60.degree. C., and a polymerization reaction was
allowed to proceed for 6 hours while carbon dioxide was being fed
to the reaction system to compensate for the carbon dioxide
consumed by the reaction.
[0108] After completion of the reaction, the autoclave was cooled
and depressurized, and the reaction mixture was filtered, thereby
giving 80.8 g of polypropylene carbonate. The obtained
polypropylene carbonate had a weight average molecular weight of
336,000 (Mw/Mn=9.02).
Example 1
[0109] In accordance with the formulation shown in Measurement
Example 1 of Table 1, 0.62 parts by mass of maleic acid modified
polypropylene (acid modified PP, manufactured by Mitsui Chemicals,
Inc., trade name: Admer QE800, MFR=9.1 g/10 min), and 3.11 parts by
mass of the polypropylene carbonate (PPC) obtained in Production
Example 1 were kneaded using a kneader (Micro 15 cc Twin Screw
Compounder manufactured by DSM) at a preset temperature of
160.degree. C. and a rotation speed of 50 rpm for 15 minutes to
obtain a molten mixture. The mixture was molded by hot pressing,
thereby giving pellets.
[0110] Subsequently, 3.73 parts by mass of the obtained pellets and
100 parts by mass of polypropylene (PP) (manufactured by Japan
Polypropylene Corporation, Mw=380,000, Mw/Mn=4.9) were kneaded at a
preset temperature of 180.degree. C. and a rotation speed of 50 rpm
for 3 minutes to obtain a molten mixture. The mixture was molded by
hot pressing, thereby preparing test specimens for the tensile
test.
Comparative Example 1
[0111] The procedure of Example 1 was repeated using only
polypropylene, without using the pellets obtained by melt-kneading
maleic acid modified polypropylene and polypropylene carbonate,
thereby preparing test specimens.
Measurement Example 1
[0112] The test specimen obtained in Example 1 was measured for
crystallization temperature, melting temperature, and crystallized
form. In accordance with the procedure described in Evaluation (5)
above, a tensile test was conducted at a tension rate of 120 mm/min
using the test specimen, and the yield stress, necking stress,
breaking stress, and breaking strain were measured. Table 1 shows
the results. FIG. 1 shows the results of a small-angle X-ray
scattering measurement conducted in accordance with the procedure
described in Evaluation (3) above.
Comparative Measurement Example 1
[0113] The test specimen obtained in Comparative Example 1 was
measured for crystallization temperature, melting temperature, and
crystallized form. A tensile test was also conducted in the same
manner as in Measurement Example 1, and the physical properties
were measured. Table 1 shows the results. FIG. 1 shows the results
of a small-angle X-ray scattering measurement conducted in the same
manner as in Measurement Example 1.
Measurement Example 2
[0114] A tensile test was conducted using the test specimen
obtained in Example 1 in the same manner as in Measurement Example
1 except that the tension rate was 80 mm/min in place of 120 mm/min
to thereby measure the physical properties. Table 1 shows the
results.
Comparative Measurement Example 2
[0115] A tensile test was conducted using the test specimen
obtained in Comparative Example 1 in the same manner as in
Measurement Example 1 except that the tension rate was 80 mm/min in
place of 120 mm/min to thereby measure the physical properties.
Table 1 shows the results.
Measurement Example 3
[0116] A tensile test was conducted using the test specimen
obtained in Example 1 in the same manner as in Measurement Example
1 except that the tension rate was 40 mm/min in place of 120 mm/min
to thereby measure the physical properties. Table 1 shows the
results.
Comparative Measurement Example 3
[0117] A tensile test was conducted using the test specimen
obtained in Comparative Example 1 in the same manner as in
Measurement Example 1 except that the tension rate was 40 mm/min in
place of 120 mm/min to thereby measure the physical properties.
Table 1 shows the results.
TABLE-US-00001 TABLE 1 Formulation Differential Scanning (Parts by
Mass) Calorimetry Tensile Test Tension Acid Crystallization Melting
Yield Necking Breaking Rate Modified Temperature Temperature Stress
Stress Stress Breaking (mm/min) PP PPC PP (.degree. C.) (.degree.
C.) (MPa) (MPa) (MPa) Strain Measurement 120 100 3.11 0.62 115 164
37 24.4 44.7 9.4 Example 1 Comparative 120 100 -- -- 114 164 38.3
24.8 38.7 6.7 Measurement Example 1 Measurement 80 100 3.11 0.62 --
-- 38.3 26.1 48.5 10.5 Example 2 Comparative 80 100 -- -- -- --
37.4 25.2 43.8 8.9 Measurement Example 2 Measurement 40 100 3.11
0.62 -- -- 37.5 28.2 48.3 11 Example 3 Comparative 40 100 -- -- --
-- 36.6 28.5 46.1 10 Measurement Example 3
Comparative Example 2
[0118] A test specimen for a tensile test was prepared in the same
manner as in Example 1 except that 0.62 parts by mass of a graft
copolymer compatibilizer (trade name: Modiper A4300 manufactured by
NOF Corporation, a graft copolymer having as a main chain a polymer
subchain consisting of ethylene-derived monomer units and glycidyl
methacrylate-derived monomer units (glycidyl methacrylate content:
15 wt %) and as a side chain a polymer subchain consisting of
n-butyl acrylate-derived monomer units and methyl
methacrylate-derived monomer units (methyl methacrylate content: 30
wt %), the side chain is present in an amount of 30 wt %,
[.eta.]=0.76 dl/g) was used in place of 0.62 parts by mass of
maleic acid modified polypropylene.
Comparative Measurement Example 4
[0119] A tensile test was conducted using the test specimen
obtained in Comparative Example 2 in the same manner as in
Measurement Example 1 to measure the physical properties. However,
the test specimen was torn apart during measurement, and the
physical properties could not be measured.
[0120] As shown in Table 1, Example 1 and Comparative Example 1
revealed that there was no change in the crystallization
temperature and the melting temperature of the polyolefin-based
resin composition according to the present invention. The
measurement results of small-angle X-ray scattering shown in FIG. 1
revealed that the pattern of the polyolefin-based resin composition
is the same as that of polypropylene. These results indicate that
the aliphatic polycarbonate resin and the acid modified
polypropylene had no influence on the crystalline form,
crystallinity, and crystalline morphology (size of spherulites) of
the polyolefin-based resin.
[0121] The results of the tensile test shown in Table 1 revealed
that the polyolefin-based resin composition according to the
present invention is excellent in mechanical strength and
elasticity. In particular, the polyolefin-based resin composition
according to the present invention has mechanical strength
equivalent to or higher than that of polypropylene, while
exhibiting significantly higher elasticity than polypropylene. This
was more noticeable as the tension rate became higher.
* * * * *